Greeting for the day!
I have a question in my mind and looking for answer from some days. If my understanding is correct then only diff between Instance and object is :-
instance means just creating a reference(copy) .
object :means when memory location is associated with the object( is a runtime entity of the class) by using the new operator
Now i want to know how to create an instance of an object. Please give explanation with sample code
Any help will be appreciated. Thanks
By your explanation it's not called an instance, but a reference of an object. An instance of a class is called an object. I think your question is: "What is the difference of an object and a reference variable?" I'll try to explain it with some examples:
Foo f;
I just declared a reference variable. This is not an object but only a reference that refers to an object.
f = new Foo();
Now I created a new object and assigned it to the f reference variable so every time I do something to f I refer to the Foo object. Like when I call f.Name = "MyFoo"; I refer to the foo object.
Foo otherFoo;
Now I declare another reference variable.
otherFoo = f;
What we have here now is having ONE object in the memory but TWO reference variables refering to the same object.
f.IsFoo = true;
bool isotherFooFoo = otherFoo.IsFoo;
This last line will return true because we changed the IsFoo property to true and f and otherFoo reffer to the same object.
I hope that explains you everything. :)
You don't create "an instance of an object", you create an instance of a class (or struct). An object is an instance of a class.
If you do:
Foo f = new Foo();
You create an instance of the Foo class.
In the phrase "an object is an instance of a class", the word "instance" does not really have a technical meaning that is different to the word "object", it is just a way of defining, in English, what the word "object" means. The meaning of "instance" is really meant to be the same as the meaning of "object". We can break this down as follows:
an object is an instance of a class
an object = instance of a class
an object = instance
In C# 9.0 there is a new way to initialize a class by Target-typed new expressions.
You can initialize the class like this:
Foo f = new();
Note, f is a reference to the class Foo.
We have a class ABC
Class ABC
{
string name="";
public ABC()
{
this.name = "A1";
}
public ABC(name)
{
this.name = name;
}
}
An Instance of a class can be created as:
ABC a1 = new ABC();
or
ABC a1 = new ABC("James");
You create instance of a class and not the object.
